Optical-path folding-element with an extended two degree of freedom rotation range

ABSTRACT

Actuators for rotating an optical-path-folding-element with two, first and second, degrees of freedom in an extended rotation range around two respective rotation axes, folded cameras including such actuators and dual-cameras including a folded camera as above together with an upright camera.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application from U.S. patentapplication Ser. No. 16/615,310 filed Nov. 20, 2019, which was a 371application from international patent application PCT/IB2019/053315filed Apr. 22, 2018, and is related to and hereby claims the prioritybenefit of commonly-owned and co-pending U.S. Provisional PatentApplication No. 62/661,158 filed Apr. 23, 2017, which is incorporatedherein by reference in its entirety.

FIELD

The subject matter disclosed herein relates in general to a folded-lensand to digital cameras with one or more folded lens.

BACKGROUND

In recent years, mobile devices such as cell-phones (and in particularsmart-phones), tablets and laptops have become ubiquitous. Many of thesedevices include one or two compact cameras including, for example, amain rear-facing camera (i.e. a camera on the back face of the device,facing away from the user and often used for casual photography), and asecondary front-facing camera (i.e. a camera located on the front faceof the device and often used for video conferencing).

Although relatively compact in nature, the design of most of thesecameras is similar to the traditional structure of a digital stillcamera, i.e. it comprises a lens module (or a train of several opticalelements) placed on top of an image sensor. The lens module refracts theincoming light rays and bends them to create an image of a scene on thesensor. The dimensions of these cameras are largely determined by thesize of the sensor and by the height of the optics. These are usuallytied together through the focal length (“f”) of the lens and its fieldof view (FOV)—a lens that has to image a certain FOV on a sensor of acertain size has a specific focal length. Keeping the FOV constant, thelarger the sensor dimensions (e.g. in a X-Y plane), the larger the focallength and the optics height.

A “folded camera module” structure has been suggested to reduce theheight of a compact camera. In the folded camera module structure, anoptical path folding element (referred to hereinafter as “OPFE” thatincludes a reflection surface such as a prism or a mirror; otherwisereferred to herein collectively as a “reflecting element”) is added inorder to tilt the light propagation direction from a first optical path(e.g. perpendicular to the smart-phone back surface) to a second opticalpath, (e.g. parallel to the smart-phone back surface). If the foldedcamera module is part of a dual-aperture camera, this provides a foldedoptical path through one lens module (e.g. a Tele lens). Such a camerais referred to herein as a “folded-lens dual-aperture camera” or a“dual-aperture camera with a folded lens”. In some examples, the foldedcamera module may be included in a multi-aperture camera, e.g. togetherwith two “non-folded” camera modules in a triple-aperture camera.

A folded-lens dual-aperture camera (or “dual-camera”) with an auto-focus(AF) mechanism is disclosed in Applicant's US published patentapplication No. 20160044247.

SUMMARY

According to one aspect of the presently disclosed subject matter thereis provided an actuator for rotating an OPFE in two degrees of freedomin an extended rotation range a first sub-assembly, a secondsub-assembly and a stationary sub-assembly, the first sub-assemblyconfigured to rotate the OPFE relative to the stationary sub-assembly inan extended rotation range around a yaw rotation axis and the secondsub-assembly configured to rotate the OPFE relative to the firstsub-assembly in an extended rotation range around a pitch rotation axisthat is substantially perpendicular to the yaw rotation axis; a firstsensor configured to sense rotation around the yaw rotation axis and asecond sensor configured to sense rotation around the pitch rotationaxis, the first and second sensors being fixed to the stationarysub-assembly, wherein at least one of the first sensor or the secondsensor is a magnetic flux sensor; and a voice coil motor (VCM)comprising a magnet and a coil, wherein the magnet is fixedly attachedto one of the first sub-assembly or the second sub-assembly, wherein thecoil is fixedly attached to the stationary sub-assembly, wherein adriving current in the coil creates a force that is translated to atorque around a respective rotation axis, and wherein the second sensoris positioned such that sensing by the second sensor is decoupled fromthe rotation of the OPFE around the yaw rotation axis.

In addition to the above features, the actuator according to this aspectof the presently disclosed subject matter can optionally comprise one ormore of features (i) to (xxv) listed below, in any technically possiblecombination or permutation:

-   -   i. wherein the actuator is adapted to be installed and operable        in a folded digital camera for rotating the OPFE within the        camera,    -   ii. wherein the actuator comprises a first actuation mechanism        (including a first VCM) configured to rotate the first        sub-assembly around the yaw rotation axis and a second actuation        mechanism (including a second VCM) configured to rotate the        second sub-assembly around the yaw rotation axis,    -   iii. wherein the actuator comprises a first sensing mechanism        that comprises the first sensor and a respective first magnet        configured to sense the rotation around the yaw rotation axis        and a second sensing mechanism that comprises the second sensor        and a second magnet configured to sense the rotation around the        pitch rotation axis,    -   iv. wherein the yaw rotation axis passes through the second        sensor to thereby decouple the second sensor from rotation        around the yaw axis,    -   v. wherein the yaw rotation axis passes through a center of the        second sensor,    -   vi. wherein the actuator further comprises a first curved        ball-guided mechanism operative to enable the rotation around        the pitch axis, and a second curved ball-guided mechanism        operative to enable the rotation around the yaw axis,    -   vii. wherein the actuator further comprises a curved ball-guided        mechanism operative to enable the rotation around the yaw axis,        the curved ball-guided mechanism is located on a side of the        OPFE which is opposite to side facing an image sensor,    -   viii. wherein the extended rotation range is equal to or greater        than ±5 degrees around the pitch and yaw rotation axes,    -   ix. wherein the extended rotation range is equal to or greater        than ±10 degrees the pitch and yaw rotation axes,    -   x. wherein the extended rotation range is between ±15-40 degrees        around the pitch and yaw rotation axes,    -   xi. wherein the extended rotation range around the pitch        rotation axis is different from the extended rotation range        around the second rotation axis,    -   xii. wherein the at least one voice coil motor includes a pitch        magnet and a coil dedicated for generating the rotation around        the pitch rotation axis and wherein the pitch magnet is designed        with a flat surface facing the coil,    -   xiii. wherein the magnetic sensor is a magnetic flux sensor such        as a Hall sensor.    -   xiv. wherein the actuator comprises a sensing mechanism that        includes the first sensor and a magnet (e.g. yaw sensing        magnet), the magnet is shaped or formed such that a central part        of the sensing magnet is further away from a projection line of        motion of the first sensor, relative to an end of the sensing        magnet,    -   xv. wherein the actuator comprises a sensing magnet (e.g. yaw        sensing magnet) shaped such that width of a cross section of the        sensing magnet increases from a point substantially at its        center towards each end of the magnet, thereby resulting in a        variable distance between the first sensor and the magnet when        relative movement occurs between the sensing magnet and the        sensor,    -   xvi. wherein the actuator further comprises a first magnet-yoke        pair which pulls the first sub-assembly to the second        sub-assembly in a radial direction relative to the pitch        rotation axis and a second magnet-yoke pair which pulls the        first sub-assembly to the stationary sub-assembly in a radial        direction relative to the yaw rotation axis,    -   xvii. wherein the first sub-assembly comprises a middle moving        frame, the second sub-assembly comprises an OPFE holder, and the        stationary sub-assembly comprises a base; wherein the first        magnet-yoke pair pulls the OPFE holder to middle moving frame        and the second magnet-yoke pair pulls the middle moving frame to        the base,    -   xviii. wherein the first sub-assembly comprises a middle moving        frame and the second sub-assembly comprises an OPFE holder, and        the stationary sub-assembly comprises a base; wherein rotation        around the yaw rotation axis is generated by rotating the middle        moving frame relative to the base and rotation around the pitch        rotation axis is generated by rotating the OPFE holder relative        to the middle moving frame,    -   xix. wherein the actuator comprises a magnet characterized by a        cut sphere shape and a coil characterized by a circular shape,        the coil is symmetrically positioned around the cut sphere,    -   xx. wherein the actuator comprises a single magnet that is used        for creating an actuation force for rotation around the yaw        rotation axis, creating a pre-load force in a magnet-yoke pair        for holding together the first sub-assembly and the stationary        sub-assembly, and sensing the rotation around the yaw rotation        axis.    -   xxi. wherein the actuator comprises only one magnetic flux        sensor that is used for sensing rotation around the yaw rotation        axis,    -   xxii. wherein the single magnet is a polarization magnet        characterized by continuous changes in direction of a magnetic        field of the magnet along the magnet's length. wherein the first        and second sensing mechanisms are decoupled from each other,    -   xxiii. wherein the actuator is designed to be installed in a        folded camera that comprises a lens module accommodating a        plurality of lens elements along an optical axis; wherein the        OPFE redirects light that enters the folded camera from a        direction of a view section along a first optical path to a        second optical path that passed along the optical axis,    -   xxiv. wherein the actuator comprises a pitch magnet located at a        side of the OPFE that is opposite to the side facing the view        section,    -   xxv. wherein the actuator comprises a yaw magnet located at a        side of the OPFE that is opposite to the side facing the lens        module,

According to another aspect of the presently disclosed subject matterthere is provided a folded camera comprising the actuator according tothe previous aspect.

In addition to the above features, the folded camera according to thisaspect of the presently disclosed subject matter can optionally compriseone or more of features (i) to (xxv) listed above, in any technicallypossible combination or permutation.

According to yet another aspect of the presently disclosed subjectmatter there is provided an actuator for rotating an OPFE with a firstdegree of freedom (DOF) around a first rotation axis and a second DOFaround a second rotation axis, comprising:

a) a first actuation mechanism for rotation in the first DOF;

b) a first sensing mechanism for sensing movement in the first DOF;

c) a second actuation mechanism for rotation in the second DOF; and

d) a second sensing mechanism for sensing movement in the second DOF;

wherein first and second actuation mechanisms are configured to rotatethe OPFE around the respective first or second rotation axis in anextended rotation range,

and wherein in some examples the first and second actuation mechanismare voice coil motors and the second sensing mechanism comprises asensor positioned such that rotation of the OPFE around the firstrotation axis is decoupled from the second sensor.

In addition to the above features, the camera according to this aspectof the presently disclosed subject matter can optionally comprise one ormore of features (i) to (xxv) listed above, in any technically possiblecombination or permutation.

According to another aspect of the presently disclosed subject matterthere is provided a sensing mechanism for sensing rotation movementaround a rotation axis, comprising a magnet and a magnetic sensorconfigured to detect a magnetic flux of the magnet and to determine arelative shift between the magnet and the magnetic sensor based onchange in the detected magnetic flux, wherein the magnet is shaped suchthat a cross section of the magnet has a width that increases from apoint substantially at a center of the magnet towards each end of themagnet, thereby increasing a range of detectable change in the magneticflux and increasing a corresponding detectable range of the relativeshift between the magnet and the magnetic sensor.

In addition to the above features, the actuator according to this aspectof the presently disclosed subject matter can optionally comprise one ormore of features (i) to (iv) listed below, in any technically possiblecombination or permutation:

-   -   i. wherein the detectable range of relative shift between the        magnet and the magnetic sensor is of more than 0.8 mm,    -   ii. wherein the detectable range of relative shift between the        magnet and the magnetic sensor is of more than 1.0 mm,    -   iii. wherein the detectable range of relative shift between the        magnet and the magnetic sensor is of more than 2.0 mm, and    -   iv. wherein the magnetic sensor is a Hall bar sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting examples of the presently disclosed subject matter aredescribed below with reference to figures attached hereto that arelisted following this paragraph. Identical structures, elements or partsthat appear in more than one figure may be labeled with the same numeralin the figures in which they appear. The drawings and descriptions aremeant to illuminate and clarify embodiments disclosed herein, and shouldnot be considered limiting in any way.

FIG. 1A illustrates a folded camera with an optical path folding element(OPFE) with an extended 2 degrees-of-freedom (DOF) rotation range,according to some examples of the presently disclosed subject matter;

FIG. 1B shows the folded camera of FIG. 1A with an OPFE actuator,according to some examples of the presently disclosed subject matter;

FIG. 1C shows a dual-camera the includes a folded camera as in FIG. 1Atogether with an upright (non-folded) camera, according to according tosome examples of the presently disclosed subject matter;

FIG. 2A shows an OPFE actuator of the folded camera of FIG. 1 in anisometric view, according to some examples of the presently disclosedsubject matter;

FIG. 2B shows the actuator in FIG. 2A without a shield, according tosome examples of the presently disclosed subject matter;

FIG. 3A shows a top actuated sub-assembly of the actuator of FIGS. 2Aand 2B from one side, according to some examples of the presentlydisclosed subject matter;

FIG. 3B shows the top actuated sub-assembly of FIG. 3A from an oppositeside, according to some examples of the presently disclosed subjectmatter;

FIG. 3C shows the top actuated sub-assembly of FIG. 3A in an explodedview, according to some examples of the presently disclosed subjectmatter;

FIG. 4A shows a bottom actuated sub-assembly of the actuator of FIGS. 2Aand 2B from one side, according to some examples of the presentlydisclosed subject matter;

FIG. 4B shows the bottom actuated sub-assembly of FIG. 4A from anopposite side, according to some examples of the presently disclosedsubject matter;

FIG. 4C shows the bottom actuated sub-assembly in an exploded view,according to some examples of the presently disclosed subject matter;

FIG. 5A shows the top and bottom actuated sub-assemblies installedtogether in an isometric view, according some examples of the presentlydisclosed subject matter;

FIG. 5B shows the top and bottom actuated sub-assemblies installedtogether in a cut along a line A-B shown in FIG. 5A, according to someexamples of the presently disclosed subject matter;

FIG. 6A shows a stationary sub-assembly of the actuator of FIGS. 2A and2B from one side, according to some examples of the presently disclosedsubject matter;

FIG. 6B shows the stationary sub-assembly of FIG. 6A from an oppositeside, according to some examples of the presently disclosed subjectmatter;

FIG. 6C shows the stationary actuated sub-assembly in an exploded view,according to some examples of the presently disclosed subject matter;

FIG. 7 shows the actuator of FIG. 2B along a cut along line A-B shown inFIG. 2A, according to some examples of the presently disclosed subjectmatter;

FIG. 8 shows details of an electronic circuitry included in thestationary sub-assembly of FIGS. 6A-6C, according to some examples ofthe presently disclosed subject matter;

FIG. 9A shows a pitch actuation and sensing mechanism of the actuator inFIGS. 2A-2B in an isometric view, according to some examples of thepresently disclosed subject matter;

FIG. 9B shows a side cut along a line A-B shown in FIG. 9A of the pitchactuation and sensing mechanism of FIG. 9A, according to some examplesof the presently disclosed subject matter;

FIG. 10A shows a pitch actuation and sensing mechanism of the actuatorin FIGS. 2A-2B in an isometric view, according to other examples of thepresently disclosed subject matter;

FIG. 10B shows a side cut of the pitch actuation and sensing mechanismof FIG. 10A along a line A-B shown in FIG. 10A, according to someexamples of the presently disclosed subject matter;

FIG. 11A shows a yaw sensing mechanism of the actuator in FIGS. 2A-2B,according to some examples of the presently disclosed subject matter;

FIG. 11B shows a yaw rotation range β, a distance R_(YAW) between a yawHall bar element and a yaw rotation axis, and a trajectory of a yawsensing magnet of the yaw sensing mechanism of FIG. 11A in the Y-Zplane, according to some examples of the presently disclosed subjectmatter;

FIG. 11C shows one magnetic configuration for the yaw sensing magnet ofFIG. 11B in a cut along a line A-B shown in FIG. 11A, according to someexamples of the presently disclosed subject matter;

FIG. 11D shows another magnetic configuration for the yaw sensing magnetof FIG. 11B in a cut along a line A-B shown in FIG. 11A, according tosome examples of the presently disclosed subject matter;

FIG. 11E shows yet another magnetic configuration for the yaw sensingmagnet of FIG. 11B in a cut along a line A-B shown in FIG. 11A,according to some examples of the presently disclosed subject matter;

FIG. 11F shows the magnetic field as a function of rotation along agiven trajectory for the cases presented in FIGS. 11C-E, according tosome examples of the presently disclosed subject matter;

FIG. 11-i to FIG. 11-vi show various possible alternative examples ofmagnetic configuration for the yaw sensing magnet.

FIG. 12A shows a yaw magnetic actuation mechanism in an isometric viewfrom one side, according to some examples of the presently disclosedsubject matter

FIG. 12B shows the yaw magnetic actuation mechanism of FIG. 12A in anisometric view from another side, according to some examples of thepresently disclosed subject matter;

FIG. 12C shows magnetic field directions in a Y-Z plane along a cut A-Bin FIG. 12A, according to some examples of the presently disclosedsubject matter;

FIG. 13 shows additional magnetic yoke positioned next to yaw magnet,according to some examples of the presently disclosed subject matter;

FIG. 14A is a schematic illustration of a stitched image generated fromfour Tele images, according to some examples of the presently disclosedsubject matter;

FIG. 14B is a schematic illustration of a stitched image generated fromsix Tele images, according to some examples of the presently disclosedsubject matter;

FIG. 14C is a schematic illustration of a stitched image generated fromnine Tele images, according to some examples of the presently disclosedsubject matter;

FIG. 15A is a cross section of top actuated sub-assembly and bottomactuated sub-assembly installed together along a cut along line A-Bshown in FIG. 15B, according to other examples of the presentlydisclosed subject matter;

FIG. 15B is an isometric view of top actuated sub-assembly and bottomactuated sub-assembly installed together of the example shown in FIG.15A, according to other examples of the presently disclosed subjectmatter;

FIG. 15C is an isometric view of top actuated sub-assembly and bottomactuated sub-assembly installed together, showing an external yoke,according to other examples of the presently disclosed subject matter;

FIG. 15D is a schematic illustration of a single polarization magnet,according to some examples of the presently disclosed subject matter;and

FIG. 15E is a schematic illustration of the magnetic field linesdirections in a Y-Z plane of the single polarization magnet illustratedin FIG. 15D, according to some examples of the presently disclosedsubject matter.

DETAILED DESCRIPTION

For the sake of clarity, the term “substantially” is used herein toimply the possibility of variations in values within an acceptable rangeas would be known to a person skilled in the art. According to oneexample, the term “substantially” used herein should be interpreted toimply possible variation of up to 10% over or under any specified value.According to another example, the term “substantially” used hereinshould be interpreted to imply possible variation of up to 5% over orunder any specified value. According to a further example, the term“substantially” used herein should be interpreted to imply possiblevariation of up to 2.5% over or under any specified value. For example,the phrase substantially perpendicular should be interpreted to includepossible variations from exactly 90°.

FIG. 1A illustrates a folded camera 100 with a 2 degrees-of-freedom(DOF) optical path folding element (OPFE) with an extended rotationrange, according to an example of the presently disclosed subjectmatter. An orthogonal X-Y-Z coordinate (“axis”) system shown appliesalso to all following drawings. This coordinate system is exemplary onlyand should not be construed as limiting. In some examples, the term“extended rotation range” used herein is used to describe a rotationrange larger than the 2-3 degrees necessary for another application, forexample optical image stabilization (OIS). In an example, an extendedrotation range may be a range equal to or greater than ±5 degrees ineach DOF relative to an OPFE zero state (as defined below). According toanother example, an extended rotation range may be a range equal to orgreater than ±10 degrees in each DOF relative to an OPFE zero state (asdefined below). According to yet another example, an extended rotationrange may be a range between ±15-40 degrees in each DOF relative to anOPFE zero state (as defined below). The extended rotation range may ormay not be equal in the two DOF. In an example, the extended rotationrange may be twice or more in the yaw DOF than in the pitch DOF, becausethe optical effect (shift of image on the image sensor) of pitchrotation is double the optical effect of yaw rotation.

Camera 100 includes a lens assembly or lens module (or simply “lens”)102, an OPFE 104 and an image sensor 106. In general lens module 102comprises a plurality of lens elements positioned along an optical axis,for example between 3 to 7 lens elements. In some examples, lens 102 hasa fixed focal length “f”. In other examples, lens 102 has a variablefocal length (zoom lens). In some examples, lens 102 may be a lensdesigned for folded cameras described for example in co-owned U.S. Pat.No. 9,392,188. OPFE 104 has a reflection surface (e.g. it may be amirror or a prism).

OPFE 104 folds light from a first optical path 108 to a second opticalpath 110. First optical path 108 extends from the direction of a viewsection 114 (facing an object or scene) towards OPFE 104 and issubstantially parallel to the X axis (in the exemplary coordinatesystem). Second optical path 110 extends from OPFE 104 towards imagesensor 106 and is substantially parallel to the Z axis (in the exemplarycoordinate system).

View section 114 may include, for example, one or more objects, a sceneand/or a panoramic view, etc. According to the illustrated example, axis110 is aligned with the optical axis of lens 102, and therefore is alsoreferred to herein as “lens optical axis” Image sensor 106 may bealigned with a plane substantially perpendicular to axis 110 (a planethat includes the X and Y axes). Image sensor 106 may output an outputimage. The output image may be processed by an image signal processor(ISP—not shown), the processing including for example, demosaicing,white balance, lens shading correction, bad pixel correction and otherprocesses that may be carried out by an ISP. In some embodiments, theISP (or some functionalities of the ISP) may be part of image sensor106.

It is noted that while the OPFE and some of the parts described belowmay be configured to rotate in two DOF, all the figures, the descriptionand the directions therein show the OPFE in a “zero” state (withoutrotation) unless otherwise mentioned.

For the sake of clarity of the description and by way of a non limitingexample only, it is defined that at zero state the first optical path108 extending from the direction of view section 114 towards the OPFE104 is perpendicular to a zero plane. The term “zero plane” as usedherein refers to an imaginary plane on which an actuator 202 describedbelow is positioned and is parallel to the lens optical axis. Forexample, in a mobile phone, the zero plane is a plane parallel to thescreen of the phone.

Furthermore, in zero state the reflecting surface of the OPFE ispositioned such that light along the first optical path 108 isredirected to a second optical path 108 that coincides with lens opticalaxis 110. Notably, the above definition is assumed to be true for thecenter of the field of view (FOV).

Yaw rotation can be defined as rotation around an axis substantiallyparallel to the first optical path in zero state. Pitch rotation can bedefined as rotation around an axis substantially perpendicular to theyaw rotation axis and the lens optical axis.

In some examples, camera 100 may further include a focus or autofocus(AF) mechanism (not shown), allowing to move (or “shift” or “actuate”)lens 102 along axis 110. The AF mechanism may be configured to adjustthe focus of the camera on view section 114. Adjusting the focus on viewsection 114 may bring into focus one or more objects and/or take out offocus one or more objects that may be part of view section 114,depending on their distance from OPFE 104. For simplicity, thedescription continues with reference only to AF mechanisms, with theunderstanding that it also covers regular (manual) focus.

An AF mechanism may comprise an AF actuation mechanism. The AF actuationmechanism may comprise a motor that may impart motion such as a voicecoil motor (VCM), a stepper motor, a shape memory alloy (SMA) actuatorand/or other types of motors. An AF actuation mechanism that comprises aVCM may be referred to as a “VCM actuator”. Such actuation mechanismsare known in the art and disclosed for example in Applicant's co-ownedinternational patent applications PCT/IB2015/056004 andPCT/IB2016/055308. In some embodiments, camera 100 may include anoptical image stabilization (OIS) actuation mechanism (not shown) inaddition to, or instead of, the AF actuation mechanism. In someembodiments, OIS may be achieved by shifting lens 102 and/or imagesensor 106 in one or more directions in the X-Y plane, compensating fortilt of camera 100 around the Z and Y directions. A three-degrees offreedom (3-DOF) OIS and focus actuation mechanism (which performs twomovements for OIS and one for AF) may be of VCM type and known in theart, for example as disclosed in international patent applicationPCT/US2013/076753 and in US patent application 2014/0327965. In otherembodiments, OIS may be achieved by shifting the lens in one direction(i.e. the Y direction), perpendicular to both the first and secondoptical paths, compensating for tilt of camera 100 around the Zdirection (lens optical axis). In this case, a second OIS operation,compensating for tilt of camera 100 around the Z direction may be doneby tilting the OPFE around the Y axis, as demonstrated below. Moreinformation on auto-focus and OIS in a compact folded camera may befound in Applicant's co-owned international patent applicationsPCT/IB2016/052143, PCT/IB2016/052179 and PCT/IB2016/053335.

Camera 100 is designed with a capability to rotate OPFE 104 with atleast two DOF (2-DOF) in an extended rotation range. Rotation can bedone for example using OPFE actuator 120, seen in FIG. 1B. Two-DOFrotation may be used to describe rotation of the prism around two axes(each axis being a DOF); in camera 100, the degrees of freedom are a yawrotation 132 around yaw rotation axis 122 which is parallel to firstoptical path 108 (X axis) when in zero state as defined above, and apitch rotation 134 around a pitch rotation axis 124 which is parallel tothe Y axis. In camera 100, yaw rotation axis 122 and pitch rotation axis124 may intersect, which may reduce coupling between a pitch sensingmechanism and yaw rotation, as described below with reference to FIG. 9.In camera 100, lens optical axis 110 intersects the intersection pointof yaw rotation axis 122 and pitch rotation axis 124. In otherembodiments, this may not be the case.

As shown in FIG. 1C, camera 100 may be a part of a dual-camera 180.Dual-camera 180 comprises camera 100 and an upright camera 190. Uprightcamera 190 includes a lens 192 and an image sensor 194. Upright camera190 may further include other parts such as a shield, a focus or AFmechanism, and/or an OIS mechanism (all of which are not shown), asknown in the art. Cameras 100 and 190 may share some or all ofrespective fields of view (FOVs). According to some examples, camera 190may have a wider FOV than camera 100. In such an example, camera 100will be referred as a “Tele camera”, while camera 190 will be referredas a “Wide camera”. In such an example, a scanning mechanism of camera100 may be used to cover some or all of the FOV of camera 190, asexplained in the description below of FIGS. 14A-14C. In other examples,camera 100 may be a part of a multiple aperture camera (multi-camera)comprising more than two cameras, e.g. comprising two or more additionalupright and/or two or more additional folded cameras. Notably, whilecharacterized by extended rotation ranges, camera 100 and actuator 120may also be capable of performing small range (1-2 degree) actuationswith high accuracy, which enable OIS around any position in the extendedrotation range.

FIGS. 2A-B show OPFE actuator 120 with more details according to somenon-limiting examples of the presently disclosed subject matter. FIG. 2Ashows OPFE actuator 120 in an isometric view. OPFE actuator 120 may becovered by a shield 202 with an opening 204 through which light canenter into OPFE 104 and an opening 206 through which light can exit fromOPFE 104. FIG. 2B shows actuator 120 without shield 202. Actuator 120further includes a bottom actuated sub-assembly 220 (also referred toherein as “yaw sub-assembly” or “first sub-assembly”), a top actuatedsub-assembly 210 (also referred to herein as “pitch sub-assembly” or“second sub-assembly”), and a stationary sub-assembly 230. Top actuatedsub-assembly 210 may be operable to be rotated, and thus rotate OPFE104, around the pitch rotation axis (parallel to the Y axis) relative tobottom actuated sub-assembly 220 (pitch rotation 134), as describedbelow. Bottom actuated sub-assembly 220 may be operable to be rotated,and thus rotate OPFE 104, around the yaw rotation axis (parallel to theX axis) relative to stationary sub-assembly 230 (yaw rotation 132), asdescribed below.

As described in more detail below, according to one example, the bottom(yaw) actuated sub-assembly 220 rotates relative to a stationarysub-assembly and the top (pitch) actuated sub-assembly 210 rotatesrelative to the bottom sub-assembly, thus the bottom sub-assembly actsas a master and the top sub-assembly acts as a slave. Applicant hasfound that this design, with the bottom actuated sub-assembly used foryaw rotation and the top actuated sub-assembly used for pitch rotation,and with the bottom actuated sub-assembly serving as a master and thetop actuated sub-assembly serving as a slave, enables to maintain alower overall height of the actuator and thus to mitigate a penalty onthe folded camera height.

FIGS. 3A-C show top (pitch) actuated sub-assembly 210 with more detailsin an isometric view from one side (FIG. 3A), an isometric view fromanother side (FIG. 3B), and an exploded view (FIG. 3C), according tosome non-limiting examples of the presently disclosed subject matter.Top actuated sub-assembly 210 includes an OPFE holder (or carrier) 302that can be made, for example, by a plastic mold that fits the shape ofOPFE 104. Top actuated sub-assembly 210 further includes a permanent(fixed) pitch magnet 304. Pitch magnet 304, as well as all other magnetsin this application, can be for example a permanent magnet, made from aneodymium alloy (e.g. Nd₂Fe₁₄B) or a samarium-cobalt alloy (e.g. SmCo₅),and can be made by sintering. According to one example, pitch magnet 304is fixedly attached (e.g. glued) to OPFE carrier 302 from below(negative X direction in FIG. 3A). Hereinafter, the term “below” usedwith reference to the position of OPFE 104 refers to a side of the OPFEopposite to the side facing the view section (in the negative Xdirection relative to the view). Details of pitch magnet 304 and itsoperation are given below. In some examples, OPFE carrier 302 includes(e.g. is molded with) two pins 308.

Sub-assembly 210 may further include two ferromagnetic yokes 306.Ferromagnetic yokes 306 may be attached (e.g. glued) to OPFE holder 302on pins 308. Ferromagnetic yokes 306 may be made of a ferromagneticmaterial (e.g. iron) and have an arced (curved) shape with a center onpitch rotation axis 124. Ferromagnetic yokes 306 are pulled bypitch-pull magnets 408 (see FIGS. 4A, 4C) to attach top actuatedsub-assembly 210 to bottom actuated sub-assembly 220 as described belowwith reference to FIGS. 5A-5C. OPFE holder 302 may further include (e.g.is molded with) two parallel arc-shaped (curved) grooves 310 a and 310 b(FIG. 3B) positioned at two opposite sides of OPFE holder 302, eacharc-shaped groove having an angle α′>α, where angle α is a desired pitchstroke, as defined by optical needs. Angle α′ is shown in FIG. 5B.Arc-shaped grooves 310 a and 310 b have a center of curvature on pitchrotation axis 124 (see FIGS. 3A, 5A, 5B). OPFE holder 302 furtherincludes (e.g. is molded with) two stoppers 312 (FIG. 3A) positioned attwo opposite sides of OPFE holder 302. Stoppers 312 are used to stopOPFE 104 in a required position.

FIGS. 4A-C show bottom (yaw) actuated sub-assembly 220 with more detailsin an isometric view from one side (FIG. 4A), an isometric view fromanother side (FIG. 4B), and an exploded view (FIG. 4C). Bottom actuatedsub-assembly 220 includes a middle moving frame 402 which can be made,for example, by a plastic mold. Bottom actuated sub-assembly 220 furtherincluded four permanent (fixed) magnets: a yaw actuation magnet 404, ayaw sensing magnet 406, and two pitch-pull magnets 408. All magnets arefixedly attached (e.g. glued) to middle moving frame 402. Notably, yawmagnet 404 is located on a side of the OPFE that is opposite to the sidefacing lens module 102 in camera 100. Details of all magnets and theiroperation are given below.

Bottom actuated sub-assembly 220 further includes two stoppers 410, madefor example from a non-magnetic metal. Stoppers 410 are fixedly attached(e.g. glued) to middle moving frame 402. Stoppers 410 help to preventtop actuated sub-assembly 210 from detaching from bottom actuatedsub-assembly 220 in case of a strong external impact or drop, asdescribed in more detail below. Middle moving frame 402 includes (i.e.is molded with) two parallel arc-shaped (curved) grooves 412 (FIG. 4A)positioned at two opposite sides of middle moving frame 402, eacharc-shaped groove having an angle α″>α. Angle α″ is shown in FIG. 5B.Arc-shaped grooves 412 have a center of curvature on yaw rotation axis122 (FIG. 5B) in common with arc shaped grooves 310. Middle moving frame402 further includes (e.g. is molded with) two parallel arc-shaped (or“curved”) grooves 414 (FIG. 4B) positioned at a back side of middlemoving frame 402 (negative Z axis), each arc-shaped groove having anangle β′>β, where angle β is a required yaw stroke, as defined byoptical needs. Angle β′ is shown in FIG. 7. Arc-shaped grooves 414 havea center of curvature on yaw rotation axis 122 (FIG. 7).

FIGS. 5A-B show top actuated sub-assembly 210 and bottom actuatedsub-assembly 220 installed together. FIG. 5A shows an isometric view andFIG. 5B shows a cut along line A-B in FIG. 5A. The figures also showvarious elements described above. FIG. 5B shows actuator 120 with threeballs 512 a, 514 a and 516 a positioned in the space between grooves 310a and 412 a, and three balls 512 b, 514 b and 516 b positioned in thespace between grooves 310 b and 412 b. FIG. 5B shows only balls 512 b,514 b and 516 b and grooves 310 b and 412 b, while balls 512 a, 514 aand 516 a and grooves 310 a and 412 a are not seen (being in the unseenback side of the drawing), with understanding of them being symmetricalong plane Z-Y. The number of balls (here 3) shown in the drawing isfor the sake of example only and should not be construed as limiting. Inother embodiments, an actuator such as actuator 120 may have more orfewer of three balls (e.g. 2-7 balls) in the space between adjacentgrooves. The balls may be made of Alumina, another ceramic material,metal, plastic or other suitable materials. The balls may have forexample a diameter in the range of 0.3-1 mm. In actuator 120, grooves310 a, 301 b, 412 a, 412 b and balls 512 a, 512 b, 514 a, 514 b, 516 aand 516 b form a curved ball-guided mechanism 560 operative to impart arotation or tilt movement to an optical element (e.g. OPFE 104) uponactuation by the VCM actuator (see below). More details on ball-guidedmechanisms in actuators may be found in co-owned international patentapplications PCT/IB2017/052383 and PCT/IB2017/054088.

In some embodiments, balls having different sizes (e.g. two differentball sizes) may be used to provide smoother motion. The balls can bedivided into a large diameter (LD) group and a small diameter (SD)group. The balls in each group may have the same diameter. LD balls mayhave for example a 0.1-0.3 mm larger diameter than SD balls. A SD ballmay be positioned between two LD balls to maintain the rolling abilityof the mechanism. For example, balls 512 b and 516 b may be LD balls andball 514 b may be a SD ball (and similarly for balls 512 a-516 a). Asdescribed above, two metallic ferromagnetic yokes 306 that may befixedly attached to OPFE holder 302 face two pitch-pull magnets 408 thatmay be attached to middle frame 402. Ferromagnetic yokes 306 may pullmagnets 408 (and thus pull top actuated sub-assembly 210 to bottomactuated sub assembly 220) by magnetic force and hold a curvedball-guided mechanism 560 from coming apart. The magnetic force (e.g.acting between yoke 306 and magnets 408) that is used for preventing twoparts of a moving mechanism to be detached is referred to herein as“pre-load force”. A pitch-pull magnet 408 and its respective yoke 306may be referred to as “first magnet-yoke pair”. Ferromagnetic yokes 306and pitch-pull magnets 408 both have arc shapes, with a center on pitchrotation axis 124. The magnetic direction of pitch-pull magnets 408 isalong pitch rotation axis 124, e.g. with a north pole toward OPFE 104and a south pole away from OPFE 104. Due to the geometric and magneticdesign presented, the magnetic force (pre-load force) betweenferromagnetic yokes 306 and pitch-pull magnets 408 is kept substantiallyin a radial direction 520 with a center on pitch rotation axis 124, andnegligible tangent force, at all rotation positions, as can be seen inFIG. 5A.

Balls 512 a-516 a and 512 b-516 b prevent top actuated sub-assembly 210from touching bottom actuated sub-assembly 220. Top actuatedsub-assembly 210 is thus confined with a constant distance from bottomactuated sub-assembly 220. Curved ball-guided mechanism 560 furtherconfines top actuated sub-assembly 210 along pitch rotation axis 124.Top actuated sub-assembly 210 can only move along the path defined bycurved ball-guided mechanism 560, namely in a pitch rotation 134 aroundpitch rotation axis 124.

FIGS. 6A-C show stationary sub-assembly 230 with more details, in anisometric view from one side (FIG. 6A), an isometric view from anotherside (FIG. 6B) and an exploded view (FIG. 6C). Stationary sub-assembly230 includes a base 602 that can be made, for example, by plastic mold.Stationary sub-assembly 230 further includes electronic circuitry 608attached to base 602, shown in FIG. 6C. Details of electronic circuitry608 are given below with reference to FIG. 8. Stationary sub-assembly230 further includes a ferromagnetic yoke 606. Ferromagnetic yoke 606 ismade by ferromagnetic material (e.g. iron) and is pulled by yawactuation magnet 404 (see FIGS. 6B and 7C) to attach bottom actuatedsub-assembly 220 to stationary sub-assembly 230 as described in moredetail below. Ferromagnetic yoke 606 and yaw actuation magnet 404 may bereferred to as “second magnet-yoke pair”.

Stationary actuated sub-assembly 230 further include a stopper 610.Stopper 610 is made for example from a non-magnetic metal. Stopper 610is attached (e.g. glued) to based 602. Stopper 610 helps to preventbottom actuated sub-assembly 220 from detaching from base 602 in case ofa strong external impact or drop, as described in more detail below. Insome examples, base 602 includes (i.e. is molded with) two parallelarc-shaped (curved) grooves 612 a-d (FIG. 6A), each arc-shaped groovehaving an angle β″>β, where angle β is a required tilt stroke, asdefined by optical needs. Angle β″ is shown in FIG. 7. Arc-shapedgrooves 612 a-d may further include a center of curvature on yawrotation axis 122 (FIGS. 2C, 6A and 7), in common with arc-shapedgrooves 414 a-b.

FIG. 7 shows actuator 120 without the shield along a cut along line A-Bseen in FIG. 2A. Grooves 612 a-d are shown to share a center withgrooves 414 a-b on yaw rotation axis 122 (612 c and 612 d, which areshown in FIGS. 6B and 6C are hidden in FIG. 7). Angles β′ and β″ aredemonstrated. Groves 612 a-b are adjacent to groove 414 a while grooves612 c-d are adjacent to groove 414 b. Four balls 712 (two are shown inFIG. 7) are positioned between adjacent groove pairs 612 a and 414 a,612 b and 414 a, 612 c and 414 b, and 612 d and 414 b, one ball betweeneach adjacent groove pair. In other embodiments, actuator 120 may havemore than one ball pair in each adjacent groove pair, e.g. in the rangeof 1-4 balls. The considerations for size and materials of all balls aresimilar to those described above. Grooves 414 a-b, 612 a-d and balls 712form a second curved ball-guided mechanism 760 of actuator 120. As shownin FIG. 6 and FIG. 7, the second curved ball-guided mechanism issituated such that the grooves 612 for rotating around the yaw axis arelocated behind OPFE 104 i.e. in the positive direction along the Z axisrelative to OPFE 104 (a side opposite to the side facing the lensmodule).

As described above, ferromagnetic yoke 606 is fixedly attached to base602 facing magnet 404 (illustrated for example in FIG. 4a and FIG. 4c ).Ferromagnetic yoke 606 pulls magnet 404 (and thus pulls bottom actuatedsub-assembly 220) to stationary sub-assembly 230 by magnetic force 702(pre-load force) and thus holds curved ball-guided mechanisms 760 fromcoming apart. The direction of magnetic force 702 is marked in FIG. 7 asthe Z direction. Balls 712 prevent bottom actuated sub-assembly 220 fromtouching stationary sub-assembly 230. Bottom actuated sub-assembly 220is thus confined with a constant distance from stationary sub-assembly230. Second curved ball-guided mechanism 760 further confines bottomactuated sub-assembly 220 along the Y-axis. Bottom actuated sub-assembly220 can only move along the path defined by the curved ball-guidedmechanism 760, namely in a yaw rotation around yaw rotation axis 122.

The curved ball-guided mechanisms 560 and 760 disclosed herein providesflexibility when defining the pitch and yaw rotation axes respectively,as the curve can be adapted to the required rotation axis. Furthermore,curved ball-guided mechanisms 560 and 760 enable to execute movement ofthe top actuated sub-assembly and the bottom actuated sub-assembly byrolling over the balls confined within the grooves (rails) along thepath prescribed by the grooves, and thus help to reduce or eliminatefriction that may otherwise exist during movement between the balls andthe moving parts.

FIG. 8 shows electronic circuitry 608 with more details, according tosome examples of the presently disclosed subject matter. Electroniccircuitry 608 includes a printed circuit board (PCB) 802 and may includeprocessing circuitry. PCB 802 allows sending input and output currentsto coils 806 and 804 and to Hall bar elements 808 and 810 (describedbelow), the currents carrying both power and electronic signals neededfor operation. PCB 802 may be connected electronically to host camera(camera 100 or similar cameras) or host device (e.g. phone, computer,not shown) e.g. by wires (not shown). PCB 802 may be a flexible PCB(FPCB) or a rigid flex PCB (RFPCB) and may have several layers (e.g.2-6) as known in the art. Electronic circuitry 608 further includesthree coils, a pitch coil 804 and two yaw coils 806. Electroniccircuitry 608 further includes two Hall bar sensing elements, a pitchHall bar element 808 and a yaw Hall bar element 810. Coils 804 and 806and Hall bar elements 808 and 810 are all connected (e.g. soldered) toPCB 802. In actuator 120, pitch coil 804 and pitch Hall bar element 808are positioned below pitch magnet 304. Notably, some of the componentsmentioned as part of the electronic circuitry are also considered aspart of an actuation and sensing mechanism.

Notably, yaw rotation axis 122 is positioned as closely as possible tothe pitch sensor (e.g. Hall bar element 808). According to one example,yaw rotation axis 122 passes through pitch sensor 808, in order todecouple the sensing of the pitch sensor from the rotation around theyaw axis. When decoupled, the influence on the sensing of the pitchsensor by rotation around the yaw axis is reduced or eliminated. Morespecifically, according to one example, yaw rotation axis 122 passesthrough the center of pitch sensor 808. By positioning the yaw rotationaxis so it passes through the center of the pitch sensor, the influenceof yaw rotation on the sensing of pitch sensor can be completelyeliminated. In addition, in some designs, yaw rotation axis 122 mayoptionally pass through the center of pitch coil 804.

FIGS. 9A-B show an example of a pitch actuation and sensing mechanism(PAASM) 900 that includes pitch magnet 304, pitch coil 804 and pitchHall bar element 808. PAASM 900 may be included in actuator 120. In someembodiments, PAASM 900 may be used only for actuation (acting as anactuation mechanism for one DOF). FIG. 9A shows PAASM 900 in anisometric view and FIG. 9B shows a side cut of pitch magnet 304 along aline A-B. According to one example, pitch magnet 304 may be symmetricalong a plane that includes pitch rotation axis 124 and first opticalaxis 108. In an example, pitch magnet 304 may be fabricated (e.g.sintered) such that it has a changing magnetic field direction along itsmechanical symmetry plane, e.g. a north magnetic field facing thepositive X direction on the left side and a north magnetic field facingthe negative X direction on the right side. Pitch magnet 304 may have alength R_(PITCH) of a few millimeters (for example 2-6 mm) in parallelto pitch rotation axis 124 and substantially longer than pitch coil 804,such that its magnetic field on most lines parallel to pitch rotationaxis 124 may be considered constant. Upon driving a current in pitchcoil 804, a Lorentz force is created on pitch magnet 304; a current in aclockwise direction will create force in the positive Z direction (alongthe Z axis), while a current in counter clockwise direction will createa force in the negative Z direction. Any force on pitch magnet 304 istranslated to torque around pitch rotation axis 124, and thus topactuated subassembly 210 will rotate relative to bottom actuatedsub-assembly 220.

Pitch Hall bar element (sensor) 808, which is positioned inside pitchcoil 804, can sense the intensity and direction of the magnetic field ofpitch magnet 304 radially directed away from pitch rotation axis 124. Inother words, for any pitch orientation of top actuated sub-assembly 210,pitch Hall bar measures the intensity of the magnetic field directed inthe X direction only. Since yaw rotation axis 122 passes through pitchHall bar element 808, the effect of the yaw rotation of bottom actuatedsub-assembly 220 on the magnetic field in the X direction applied bypitch magnet 304 is reduced (e.g. eliminated) and thus any change on themeasurement of pitch Hall bar element 808 is reduced (e.g. eliminated)as well. By positioning the Hall bar element 808 such that the yawrotation axis 122 passes through its center, the effect of the yawrotation of bottom actuated sub-assembly 220 on the magnetic field inthe X direction applied by pitch magnet 304 is reduced (e g minimized)and thus any change on the measurement of pitch Hall bar element 808 ismitigated. Pitch Hall bar element 808 can thus measure the respectivepitch rotation of top actuated sub-assembly 210 while being unaffectedby the yaw rotation of bottom actuated sub-assembly.

FIGS. 10A-B show another exemplary embodiment of a PAASM numbered 1000,similar to PAASM 900. PAASM 1000 may be included in actuator 120, toreplace PAASM 900. According to one example, a pitch magnet 1004replaces pitch magnet 304. Pitch magnet 1004 is a cut of a sphere withits center positioned substantially on the intersection point of yawrotation axis 122 and pitch rotation axis 124. According to one example,a pitch coil 1006 that replaces pitch coil 804 has a circular shape witha center substantially on yaw rotation axis 122 (in some examples theyaw rotation axis passes exactly through the center of the coil). Pitchcoil 1006 may be made (fabricated) with similar considerations presentedabove for pitch coil 804. Due to the symmetry of the pitch magnet aroundyaw rotation axis 122, any yaw rotation will not influence the magneticfield of the pitch coil and thus will not change the force applied bypitch coil 1006 on pitch magnet 1004. Having a constant force forvarious yaw positions may facilitate and simplify pitch position control(close loop control or open loop control). As mentioned above, yawrotation axis passes through sensor 808 to thereby reduce the effect ofyaw rotation of bottom actuated sub-assembly 220 on the magnetic fieldin the X direction applied by pitch magnet 1004.

FIG. 11A shows a yaw sensing mechanism numbered 1100. Yaw sensingmechanism 1100 includes yaw sensing magnet 406 and yaw Hall bar element810. Yaw Hall bar element 810 can measure the intensity and direction ofthe magnetic field of yaw sensing magnet 406 directed along yaw rotationaxis 122. In other words, Hall bar element 810 measures the intensity ofmagnetic field directed in the X direction only.

FIG. 11B shows a yaw rotation range β, a distance R_(YAW) between yawHall bar element 810 and yaw rotation axis 122, and a trajectory 1108 ofyaw sensing magnet 406 in the Y-Z plane. In some examples, yaw rotationrange β is more than 10 degrees. The distance R_(YAW) is e.g. in therange of 2-5 mm. As an example, a case in which β=40° (meaning ±20° fromthe “zero” position) and R_(YAW)=2.75 mm is analyzed in FIGS. 11C-Fbelow. As bottom actuated sub-assembly 220 is yaw-rotated, trajectory1108 is in the Y-Z plane. Trajectory 1108 has an arc projection in theY-Z plane (FIG. 11B) with length β×R_(YAW), where β is calculated inradians. Trajectory 1108 has a line shape projection on the X-Y plane(FIGS. 11C-E) with Length 2×R_(YAW)×cos(β).

Yaw sensing magnet 406 is designed such that is has dimensions along Z-Ydirections and such that it covers trajectory 1108 from the top view(Y-Z plane). Yaw sensing magnet 406 can have different configurations.

FIGS. 11C-E show three different examples of magnetic configurations foryaw sensing magnet 406 in a cross section along X-Y plane of yaw sensingmechanism 1100. In the configuration of FIG. 11C, yaw sensing magnet 406has a rectangular cross section and the magnetic field of yaw sensingmagnet 406 changes direction in the middle, e.g. the north magneticfield facing the positive X direction on the left side and the northmagnetic field facing the negative X direction on the right side. In theconfiguration of FIG. 11D, yaw sensing magnet 406 has a rectangularcross section, and the magnetic field of yaw sensing magnet 406 isdirected in the Y direction.

In the configuration shown in FIG. 11E, yaw sensing magnet 406 ischaracterized, along the Y direction, by a thinner cross section (theY-X plane) in the middle and a thicker cross section on the sides. Thevarying width results in a varying distance between the sensor and themagnet positioned near the magnet (the sensor is located towards thenegative X direction relative to the magnet) and thus a varying magneticfield along a projection of trajectory 1108 (line 1114) on the Y-Xplane. In some examples, the variation around the magnetic field issymmetrical around its center such that the thickness of the crosssection of the magnet increases from a point substantially at its centertowards each end of the magnet. Various examples of magnets constructedaccording to this principle are illustrated in FIGS. 11-i to 11-vi.

In addition, in some examples of the configuration of FIG. 11E (or anyone of FIGS. 11-i to 11-vi), the magnetic field of yaw sensing magnet406 changes direction in the middle, e.g. the north magnetic field facesthe positive X direction on the left side and the north magnetic fieldfaces the negative X direction on the right side. This results in zeromagnetic field in the X direction in yaw hall bar element 810 facing thecenter of magnet 406 (along the center line).

FIG. 11F shows the magnetic field as a function of rotation alongtrajectory 1108, for the 3 cases presented in FIGS. 11C-E. Theprojection of trajectory 1108 on plane X-Y (representing a lateral shiftcomponent of the magnet shift relative to the sensor) is shown by line1110 in FIG. 11C, line 1112 in FIG. 11D and line 1114 in FIG. 11E. Forline 1110, the maximal magnetic field change along ±20 degreestrajectory is ±0.28 Tesla. However, most of the magnetic field change isobtained in a ±7 degrees trajectory and the magnetic field gradient athigher yaw angles is lower than at lower yaw angles. This limits theability to sense changes with high accuracy in high yaw angles. Forprojection line 1112, the magnetic field gradient is more uniform alongthe trajectory of ±20, comparing to projection line 1110. However, themagnetic field total change is limited to under ±0.08 Tesla. Forprojection line 1114 the magnetic field gradient is more uniform thanfor both lines 1110 and 1112, and the total magnetic field change is±0.25 Tesla, which can give high accuracy for position measurements.Thus, the magnetic configuration presented in FIG. 11E is superior forposition sensing at large strokes, relative to the distance between theHall bar and the corresponding magnet (e.g. in 1-4 mm range) usingchanges in magnetic field. Thus, by shaping the magnet with a variablethickness as shown in FIGS. 11E and 11-i to 11-vi, the range ofdetectable change in magnetic flux in increased. Accordingly, thecorresponding detectable range of relative (lateral) shift of the magnetand sensor is increased as well.

FIG. 12A-C shows a yaw magnetic actuation mechanism numbered 1200. Thisactuation mechanism is for a second DOF. FIG. 12A show isometric viewfrom one side, FIG. 12B shows isometric view from another side. Yawmagnetic actuation mechanism 1200 include yaw actuation magnet 404, yawcoils 806 and ferromagnetic yoke 606. FIG. 12C shows the magnetic fielddirections is Y-Z plane, along a cut A-B in FIG. 12A. Yaw actuationmagnet 404 may be sintered such that its magnetic field is pointedtoward negative Z direction. Each of coils 806 has one part (1202, 1204)which is positioned in close proximity to yaw actuation magnet 404 (e.g.distance of 100-300 μm), and one part (1206, 1208) which is furtherapart from yaw magnet 404. Coils 806 may be connected in serial, suchthat the current in the two coil is equal. When current in 1202 is inthe positive X direction the current in 1204 is also in the positive Xdirection, and the current in parts 1206 and 1208 is in the negative Xdirection. Upon driving a current in Yaw coils 806, a Lorentz force iscreated on the yaw magnet 404, according to d{right arrow over(F)}=Id{right arrow over (l)}×{right arrow over (B)}. The direction ofthe magnetic field is demonstrated in FIG. 12C. The Lorentz force istranslated into torque around yaw rotation axis 122.

In some examples, an additional magnetic yoke 1302 may be located nextto yaw magnet 404. This yoke may increase the intensity of the magneticfield in coils 806 and increase the torque created by yaw magneticactuation mechanism 1200. FIG. 13 shows this case.

In some examples, rotation of the reflecting element around one or twoaxes moves the position of the camera FOV, wherein in each position adifferent portion of a scene is captured in an image having theresolution of the digital camera. In this way a plurality of images ofadjacent camera FOVs (e.g. partially overlapping FOVs) are captured andstitched together to form a stitched (also referred to as “composite”)image having an overall image area of an FOV greater than digital cameraFOV.

In some examples the digital camera can be a folded Tele cameraconfigured to provide a Tele image with a Tele image resolution, thefolded Tele camera comprising a Tele image sensor and its Tele lensassembly is characterized with a Tele field of view (FOV_(T)). Accordingto some examples, the folded Tele camera is integrated in a multipleaperture digital camera that comprises at least one additional uprightWide camera configured to provide a Wide image with a Wide imageresolution, being smaller than the Tele image resolution, the Widecamera comprising a Wide image sensor and a Wide lens module with a Widefield of view (FOV_(W)); wherein FOV_(T) is smaller than FOV_(W),wherein rotation of the OPFE moves FOV_(T) relative to FOV_(W), forexample as shown in of co-owned international patent applicationsPCT/IB2016/056060 and PCT/IB2016/057366.

The description of these PCT applications includes a Tele camera with anadjustable Tele field of view. As described in PCT/IB2016/056060 andPCT/IB2016/057366, rotation of the reflecting element around one or twoaxes moves the position of Tele FOV (FOV_(T)) relative to the Wide FOV(FOV_(W)), wherein in each position a different portion a scene (withinFOV_(W)) is captured in a “Tele image” with higher resolution. Accordingto some examples, disclosed in PCT/IB2016/056060 and PCT/IB2016/057366,a plurality of Tele images of adjacent non-overlapping (or partiallyoverlapping) Tele FOVs are captured and stitched together to form astitched (also referred to as “composite”) Tele image having an overallimage area of an FOV greater than FOV_(T). According to some examples,the stitched Tele image is fused with the Wide image generated by theWide camera.

Digital camera 100 can further comprise or be otherwise operativelyconnected to a computer processing circuitry (comprising one or morecomputer processing devices), which is configured to control theoperation of the digital camera (e.g. camera CPU). The processingcircuitry, can comprise for example a controller operatively connectedto the actuator of the rotating OPFE configured to control itsoperation.

The processing circuitry can be responsive to a command requesting animage with a certain zoom factor and control the operation of thedigital camera for providing images having the requested zoom. Asmentioned in applications PCT/IB2016/056060 and PCT/IB2016/057366, insome examples a user interface (executed for example by the processingcircuitry) can be configured to allow input of user command beingindicative of a requested zoom factor. The processing circuitry can beconfigured to process the command and provide appropriate instructionsto the digital camera for capturing images having the requested zoom.

In some cases, if the requested zoom factor is a value between theFOV_(W) of a wide camera and FOV_(T) of a tele camera, the processingcircuitry can be configured to cause the actuator of the reflectingelement to move the reflecting element (by providing instruction to thecontroller of the actuator) such that a partial area of the scenecorresponding to the requested zoom factor is scanned and a plurality ofpartially overlapping or non-overlapping Tele images, each having a Teleresolution and covering a portion of the partial area, are captured. Theprocessing circuitry can be further configured to stitch the pluralityof captured imaged together in order to form a stitched image (compositeimage) having Tele resolution and an FOV greater than the FOV_(T) of thedigital camera. Optionally the stitched image can then be fused with theWide image.

FIG. 14A is a schematic illustration of an example of a stitched image1400 generated by scanning, capturing and stitching together four Teleimages with FOV_(T), compared to the FOV_(W) of a Wide camera, as in theexample of FIG. 1C, where camera 190 represents a Wide FOV camera with aFOV_(W) coupled to folded Tele camera 100 with a FOV_(T). In FIG. 14A,1402 denotes FOV_(W), 1404 denotes FOV_(T) at the center of FOV_(W) and1406 indicates the size of the requested zoom factor. In the illustratedexample, four partially overlapping Tele images 1408 are captured.

Notably, the overall area of captured Tele images 1408 is greater thanthe area of the zoom image 1406 in the requested zoom. The central partof the captured Tele images is extracted (e.g. by the computerprocessing circuitry as part of the generation of the stitched image)for generating stitched image 1400. This helps to reduce the effect ofimage artefacts resulting from transition from an image area covered byone image to an image area covered by a different image.

FIG. 14B is a schematic illustration of an example of a stitched image1400′ generated by capturing and stitching together six Tele images.FIG. 14C is a schematic illustration of an example of a stitched image1400′ generated by capturing and stitching together nine Tele images.The same principles described with reference to FIG. 14A apply to FIGS.14B and 14C. Notably, the output image resulting from the stitching canhave a different width to height ratio than the single image proportion.For example, as illustrated in FIG. 14B, a single image can have a 3:4ratio and the output stitched image can have a 9:16 ratio.

It is noted that image stitching per se is well known in the art andtherefore it is not explained further in detail.

An alternative design of the top and bottom actuated sub-assembliesdescribed above is now described with reference to FIGS. 15A-15E.Notably, as would be apparent to any person skilled in the art, unlessstated otherwise, some of the details described above with reference tothe previous figures can also be applied to the example described withreference to FIGS. 15A-15E.

According to this design, a single magnet 1510 serves for threepurposes: 1) as a pre-load magnet in magnet-yoke pair, dedicated forfastening the bottom actuated sub-assembly to the stationarysub-assembly; 2) as a yaw actuation magnet dedicated for generating yawmovement of bottom actuated sub-assembly; and 3) as a yaw sensing magnetfor sensing yaw movement.

FIG. 15A shows a magnet 1506 and a yoke (e.g. a ferromagnetic plate suchas iron) 1504, where the magnet and yoke are pulled together by pre-loadforce (indicated by black double head arrow) and thus fasten topactuated sub-assembly 210 to bottom actuated sub-assembly 220. In someexamples, magnet 1506 and yoke 1504 are positioned substantially at thecenter (relative to the Y axis direction) of the top actuatedsub-assembly. Pitch rotation axis relative to the bottom actuatedsub-assembly is demonstrated by the circular arrow 1508.

FIG. 15B shows top and bottom actuated sub-assemblies in isometric view.FIG. 15B illustrates magnet 1510 located at the internal part of bottomactuated sub-assembly, sensor 1512 and a coil 1514, which is located atthe back of bottom actuated sub-assembly (in the positive Z directionrelative to magnet 1510). According to one example, a single coil can beused for actuation.

As shown in FIG. 15C, yoke 1516, is fastened to the stationarysub-assembly. Magnet 1510 and yoke 1516 are attracted by pre-load forceto thereby fasten bottom actuated sub-assembly 220 to stationarysub-assembly 230. Coil 1514 is positioned in close proximity to yawactuation magnet 1510 (e.g. distance of 100-300 μm). When current isapplied in coil 1514, a Lorentz force is created on yaw magnet 1510according to d{right arrow over (F)}=Id{right arrow over (l)}×{rightarrow over (B)}, where the Lorentz force is translated into torquearound yaw rotation axis 122 (not shown) as explained above.

Magnet 1510 moves along the yaw direction as part of the bottom actuatedsub-assembly. In addition of being more compact, this type of yawactuation mechanism also provides better efficiency, as it does notgenerate force in the opposite direction to the desired yaw movement.

As explained above, in some examples top actuated sub-assembly 210includes an OPFE holder (or carrier) 302 and bottom actuatedsub-assembly includes a middle moving frame 402. According to anexample, yoke 1504 is attached (e.g. glued) to the holder and the firstmagnet-yoke pair (1506-1504) pulls the OPFE holder to the middle movingframe. Alternatively, the position of the magnet and yoke can beswitched. The stationary sub-assembly includes a base and the yoke isattached to the based in a manner that the second magnet-yoke pair(1510-1516) pulls the middle moving frame to the base. Also, in anexample coil 1514 and sensor 1512 are fixed (e.g. glued) to the base.

According to some examples of the presently disclosed subject matter yawmagnet 1510, which also serves as yaw sensing magnet, is made to have anincreased detection range. To this end, magnet 1510 is made to have asingle magnetic polarization direction as indicated by the back arrowextending from the south pole to the north pole of magnet 1510 shown inFIG. 15D. The directions of the magnetic field lines are indicated byarrows a-e in FIG. 15D and in more detail in FIG. 15E, which is a topview of magnet 1510. As indicated by arrows a-e, as a result of thesingle magnetic polarization direction of magnet 1510, the angle of themagnetic field relative to the magnet surface changes continuously alongthe length of magnet. The illustration shows the angle changing frombeing substantially perpendicular in the positive direction at one end,to being in a parallel direction at the magnet center and to beingsubstantially perpendicular in the negative direction at the other one.Since the relative changes (e.g. of magnetic flux) are detectable ateach of the points where change in the direction of the magnetic fieldoccurs, yaw movement of the magnet relative to sensor 1512 can bedetected over an increased range. The increased detection range of theyaw magnet as disclosed herein enables to use the same magnet for bothactuation and sensing, eliminating the need for two separate magnets.

Note that unless stated otherwise terms such as “first” and “second” asused herein are not meant to imply a particular order but are only meantto distinguish between two elements or actions in the sense of “one” and“another”.

While this disclosure has been described in terms of certain embodimentsand generally associated methods, alterations and permutations of theembodiments and methods will be apparent to those skilled in the art.The disclosure is to be understood as not limited by the specificembodiments described herein, but only by the scope of the appendedclaims.

All references mentioned in this specification are herein incorporatedin their entirety by reference into the specification, to the sameextent as if each individual reference was specifically and individuallyindicated to be incorporated herein by reference. In addition, citationor identification of any reference in this application shall not beconstrued as an admission that such reference is available as prior artto the present application.

What is claimed is:
 1. A sensing mechanism for sensing rotation movementaround a rotation axis, comprising: a) a magnet; and b) a magneticsensor configured to detect a magnetic flux of the magnet and todetermine a relative shift between the magnet and the magnetic sensorbased on change in the detected magnetic flux, wherein the magnet isshaped such that a cross section of the magnet has a width thatincreases from a point substantially at a center of the magnet towardseach end of the magnet, thereby increasing a range of detectable changein the magnetic flux and increasing a corresponding detectable range ofthe relative shift between the magnet and the magnetic sensor.
 2. Thesensing mechanism of claim 1, wherein the detectable range of therelative shift between the magnet and the magnetic sensor is of morethan 0.8 mm.
 3. The sensing mechanism of claim 1, wherein the detectablerange of relative shift between the magnet and the magnetic sensor is ofmore than 1.0 mm.
 4. The sensing mechanism of claim 1, wherein thedetectable range of relative shift between the magnet and the magneticsensor is of more than 2.0 mm.
 5. The sensing mechanism of claim 1,wherein the magnetic sensor is a Hall bar sensor.
 6. The sensingmechanism of claim 2, wherein the magnetic sensor is a Hall bar sensor.7. The sensing mechanism of claim 3, wherein the magnetic sensor is aHall bar sensor.
 8. The sensing mechanism of claim 4, wherein themagnetic sensor is a Hall bar sensor.